I have a gut feeling they are gonna kill Ironhide off in this one.
Reason #1 - I have not seen any pictures of his vehicle mode in Chicage (the site in which the major climatic final battle is suppose to take place).
Reason #2 - Michael Bay wants a darker more serious tone in this movie.
Reason #3 - The GMC Topkick is no longer being produced. So you know Chevy certainly wont care.
But thats ok, because they are gonna bring Bulkhead in for movie #4!!